Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
It is well known that the use of lubrication fluids such as oils and similar substances to lubricate engines can result in the accumulation of impurities, abrasion contaminants and other unwanted by-products. An example of this is the build-up which accumulates in motor vehicle engines over time. These substances are often produced when the lubricating fluid is heated when the engine is running. These unwanted by-products include varnish, carbon deposits, mineral and acid deposits, all of which can accumulate on the internal metal surfaces of an engine. As noted above, these deposits build up as a result of heating the oil and of blow-by from the combustion processes. The extent of this build up of unwanted deposits is determined generally by the condition of the engine and the operating regime. However, contaminant build up and wear from friction is known to occur, to some extent, in all engines.
A further source of wear in an engine resides in the build up of what are known as “wear metals” in the internal volumes of the engine. Wear metals are produced by friction between moving parts of the engine. This produces a suspension of fine metal particles which are suspended in the lubricating fluid. These can accumulate where there is insufficient or low through-flow of the lubricating fluid. The presence of wear metals not only damages the engine but also adversely affects the friction reducing properties of the lubricating fluids. It can therefore contribute significantly to excess wear of metal-to-metal interfaces in the engine.
Simply changing the oil does not generally totally overcome such problems as wear metals are known to cling to or build up in the film of residual oil which is found on the most internal surfaces of the engine. When a fresh or clean batch of oil is poured into the engine, the oil film mixes with the fresh oil thus distributing the wear metal particles into the fresh oil batch. Changing the oil is also at least partly ineffective in removing varnish, carbon build ups or mineral or acid deposits.
A further contaminant found in engines is “sludge”. Sludge is produced as a result of the breakdown of lubricating oil, when combined with water, acid vapour, and exhaust gas blow-by under conditions of extreme heat and pressure. Such conditions can result from short engine run times, cool engine operating temperatures, overheating or long storage periods. Sludge clings to the internal surfaces of the engine and is not easily removed by “normal” oil changing.
It is known to use flushing solutions with either petrol or diesel engines to remove the above mentioned unwanted deposits, see the patent specifications published as U.S. Pat. No. 4,174,231 and international publication number WO95/17979.
Existing cleaning systems have little in the way of quality control to ensure that the correct fluids are used for correct amount of time and that the engine is operated correctly during cleaning.
Therefore, the user may inadvertently use the incorrect fluids, use them for too long or too short a period or under the wrong operating conditions, reducing the effectiveness of the cleaning cycle and/or potentially damaging the engine.
A problem with existing cleaning systems is that invariably a proportion of the cleaning fluid is retained within the engine. This contaminates the new oil introduced after cleaning, reducing the quality of the oil.
It is therefore an object of the present invention to provide a method and apparatus for removing waste products or undesirable build-ups from lubrication systems in engines which overcomes or at least alleviates problems in engine cleaning systems at present or at least to provide the public with a useful choice.
Further objects of the present invention may become apparent from the following description.